1. Anaphalis margaritacea (Linnaeus) Bentham & Hooker f., Gen. Pl. 2: 303. 1873.
Pearly everlasting, anaphale marguerite, immortelle blanche
Gnaphalium margaritaceum Linnaeus, Sp. Pl. 2: 850. 1753; Anaphalis margaritacea var. occidentalis Greene; A. margaritacea var. subalpina (A. Gray) A. Gray
Perennials; rhizomes relatively slender. Stems white, densely and closely tomentose, not glandular. Leaf blades 1–3-nerved, 3–10(–15) cm, bases subclasping, decurrent, margins revolute, abaxial faces tomentose or glabrescent (proximal leaves), not glandular or very sparsely and inconspicuously glandular, adaxial faces green, glabrate. Involucres 5–7 × 6–8(–10) mm. Phyllaries ovate to nearly linear (innermost), subequal to unequal, apices white, opaque. Cypselae 0.5–1 mm, bases constricted into stipiform carpopodia. 2n = 28.
Flowering Jul–Oct (sporadically longer). Dry woods, often with aspen or mixed conifer-hardwood, borders and trails, dunes, fields, roadsides, other open, often disturbed sites; 0–3200 m; St. Pierre and Miquelon; Alta., B.C. , Man., N.B., Nfld. and Labr., N.W.T., N.S., Ont., P.E.I. Que., Sask., Yukon; Alaska, Ariz., Ark., Calif., Colo., Conn., Del., Idaho, Ill., Ind., Iowa, Ky., Maine, Md., Mass., Mich., Minn., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., Ohio, Oreg., Pa., R.I., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.; Mexico (Baja California); Asia; introduced in Europe.
Anaphalis margaretacea was widely planted as an ornamental and escaped. It apparently naturalized from its native range in both Asia and North America; it is cultivated and naturalized in Europe.
Anaphalis margaritacea has the aspect of Pseudognaphalium; it differs in being subdioecious (polygamo-dioecious; the heads either staminate or primarily pistillate) and in its distinctive cypselar vestiture. It is further recognized by its combination of rhizomatous habit, subclasping-decurrent, bicolor, revolute leaves, and distally white phyllaries. Segregate species and varieties have been described among the North American plants (in addition to the two cited above), based on variation in habit, vestiture, and leaf morphology and density, but the variants appear to be more like a complex series of ecotypes rather than broader evolutionary entities.